content: /*
   * Copyright 2017 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package hu.akarnokd.reactive4javaflow;
  
  import hu.akarnokd.reactive4javaflow.functionals.AutoDisposable;
  import hu.akarnokd.reactive4javaflow.impl.*;
  
  import java.lang.invoke.*;
  import java.util.concurrent.Flow;
  
  public abstract class AbstractDisposableSubscriber<T> implements FolyamSubscriber<T>, AutoDisposable {
  
      Flow.Subscription upstream;
      static final VarHandle UPSTREAM = VH.find(MethodHandles.lookup(), AbstractDisposableSubscriber.class, "upstream", Flow.Subscription.class);
  
      protected void onStart() {
          request(Long.MAX_VALUE);
      }
  
      protected final void request(long n) {
          if (n <= 0L) {
              FolyamPlugins.onError(new IllegalArgumentException("n <= 0: " + n));
          } else {
              upstream.request(n);
          }
      }
  
      @Override
      public final void onSubscribe(Flow.Subscription s) {
          if (SubscriptionHelper.replace(this, UPSTREAM, s)) {
              onStart();
          }
      }
  
      @Override
      public final void close() {
          SubscriptionHelper.cancel(this, UPSTREAM);
      }
  }
  